JPH02173707A - Manufacture of color filter - Google Patents

Abstract

PURPOSE:To obtain a color filter whose surface is flattened effectively and to obtain a liquid crystal display element which has no picture element shift by using a press body which is provided with a space part where an alignment mark is excluded from an object to be pressed. CONSTITUTION:When the printed surface of a color filter which is printed and formed on a specific filter substrate is pressed and flattened, the press body provided with the space part where the alignment mark is excluded from the object to be pressed, i.e. a hole and a groove is used opposite an alignment mark printed and formed on the filter substrate. For example, a press body 9 where a space part (groove 8) for excluding an alignment mark 7 from the object to be pressed is used opposite, for example, the alignment mark 7. Therefore, only the printed surface of the color filter can be pressed and flattened. Consequently, while high aligning accuracy that the alignment mark has is maintained, the color filter which has the flattened color filter surface is manufactured effectively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a color filter incorporated into a large-sized liquid crystal display element.

[Prior Art] In recent years, liquid crystal display elements (LCDs) have become more dense, color displays have been made more sophisticated, and their display screens have become larger. However, liquid crystal display elements have evolved from conventional segment display to dot matrix display, and recently, the display screen structure has been improved by miniaturizing the display pixel size and arranging a large number of pixels in two dimensions (1 Iij) with a micro array pitch. , and has even reached the point where it is displayed on color TV images.

However, the reality is that liquid crystal display elements for displaying color TV images are still in practical use only with a screen size of about 2.5 to 4 inches from the viewpoint of display image quality. A major problem remains in how to increase the display screen size.

By the way, when realizing a color display type liquid crystal display element,
A color filter corresponding to each display pixel, for example, R
Individual color filters are used corresponding to pixel sizes representing the three primary colors of (red), G (green), and B (blue). This color filter is, for example, a predetermined glass substrate (
Filter board) On the I, R, G, corresponding to the pixel size,
The B color filter layers 2R, 2G, and 2B are printed and formed in correspondence with each pixel. These color filter layers 2
R, 2G.

2B is provided in a stripe shape corresponding to the arrangement pitch of pixels, for example. At this time, an alignment mark for use in alignment during assembly and production of the liquid crystal display element is also printed and formed on the glass substrate l at the same time.

However, color display type liquid crystal display elements are basically
For example, as described above, color filter layers 2R, 2G, and 2B are printed and formed on a glass substrate (filter substrate) 1, and a predetermined transparent electrode 3 is arranged and formed on the color filter, and a matrix is formed as a pair with this transparent electrode 3. This is realized by aligning a glass substrate 5 on which transparent electrodes 4 forming pixels in a shape are arranged according to the alignment marks and disposing them facing each other with a predetermined gap therebetween, and filling a liquid crystal material 6 between them. .

When a liquid crystal driving voltage is selectively applied between the transparent electrodes 3.4, the liquid crystal material 6 in the area (pixel) specified by the transparent electrode 3.4 to which this liquid crystal driving voltage is applied is oriented. Color display is performed by selectively viewing the light that changes depending on the orientation through the color filter layers 2R, 2G, and 2B provided corresponding to the regions (pixels).

[Problems to be Solved by the Invention] However, in such a liquid crystal display element, as described above, the color filter layer 2R printed on the filter substrate l,
2G and 2B, if there is a bulge peculiar to printing due to the viscosity of the printing ink, a change occurs in the gap between the transparent electrodes 3 and 4 as schematically shown in FIG. 3. In other words, the parallelism between the transparent electrodes 3 and 4 will be impaired. Such nonparallelism between the transparent electrodes 3 and 4 significantly impairs the orientation of the liquid crystal material 6 interposed therebetween, and becomes a major factor in deteriorating the quality of displayed images.

Therefore, in the past, a color filter layer 2R,
After printing and forming the color filter layers 2G and 2B, for example, by passing them through a roller, the printed surfaces are pressed to flatten (smooth) the upper surfaces (surfaces) of the color filter layers 2R, 2G, and 2B. . However, during this pressing, the alignment marks printed for alignment of the glass substrate 1.5 are also pressed, and the alignment accuracy of the alignment marks printed with high precision is lost. There was a problem. In other words, there was a problem in that the alignment mark, which was printed with high precision, was crushed by the press.

The present invention has been made in consideration of these circumstances, and its purpose is to impair the alignment accuracy of alignment marks that are printed and formed on a predetermined filter substrate together with color filters that correspond to pixels. A color filter that allows you to easily produce color filters that do not cause problems such as color shift! The purpose is to provide a two-way method.

[Means for Solving the Problems] A method for manufacturing a color filter according to the present invention includes disposing color filters corresponding to each pixel of a large screen in which a plurality of pixels are arranged in a matrix on a predetermined filter substrate. After printing and forming alignment marks for positioning on the filter substrate according to the size of the pixels, pressing the printed surface of the color filter to flatten the surface of the printing surface. The present invention is characterized in that a press body is used in which a space portion, such as a hole or a groove, for excluding the alignment mark from the press object is provided in a portion facing the alignment mark.

[Function] According to the present invention, when pressing the printed surface of a color filter printed on a predetermined filter substrate to flatten (smooth) the printed surface, the alignment mark printed on the filter substrate is pressed. Since a press body is used that has a space, such as a hole or a groove, to exclude the alignment mark from the pressing object, the press body can flatten only the printed surface of the color filter without pressing the alignment mark. can do. As a result, it is possible to effectively manufacture a color filter having a flattened (smoothed) color filter surface while maintaining the high alignment accuracy of the alignment mark.

[Example] Hereinafter, a method for manufacturing a color filter according to an example of the present invention will be described with reference to the drawings.

The method of manufacturing a color filter according to the present invention basically involves attaching a color filter corresponding to each pixel of a large screen of a liquid crystal display element, in which a plurality of pixels are arranged in a matrix, to a predetermined filter substrate. A first step of printing an alignment mark on the filter substrate (glass substrate) corresponding to the size of the pixel and for alignment outside the screen area on the filter substrate; Prior to the step of drying and solidifying the printed color filter and alignment mark, a second step of pressing the printed surface of the color filter to flatten it (smoothing), and this pressing process flattens the printed surface surface. and a third step of drying and solidifying the (smoothed) color filter to complete the color filter.

The first step uses R (red), G (green), and B (blue) printing inks, respectively, to form a red filter layer 2R.

It consists of a step of sequentially printing the green filter layer 2G and the blue filter layer 2B on a predetermined glass substrate (filter substrate) 1, for example, in a stripe shape at a predetermined pitch. This printing process is performed, for example, by shifting one printing plate at a predetermined pitch and repeating it three times with different printing ink colors.

Through this printing process, a predetermined glass base! Red, green, and blue filter layers 2+ on top of 21? , 2G, and 2B are printed alternately in stripes at a predetermined pitch corresponding to the pixel arrangement.

Incidentally, when printing the color filter, alignment marks 7 for positioning used in assembling the liquid crystal display element are also printed at the same time.

The alignment marks 7 are printed and formed on the glass substrate 1 at positions outside the display screen area, for example, at four locations on the top, bottom, left and right.

However, each color filter layer 2I printed and formed on the glass substrate 1 in this way? , 2G, 2[3, due to the viscosity of the printing ink, etc., generally have a so-called kamaboko-shaped printed cross-sectional shape with a raised central part from a microscopic perspective,
There is a difference of about 2 to 41 points in layer thickness between the center and edge portions. And striped filter layers 2R, 2 of each color.
A groove of about 1 μm is often formed between G and 2B.

In order to flatten (smooth) the printing surfaces of the color filter layers 2R, 2G, and 2B, a press treatment is performed in a second step.

In the pressing process in this second step, the present invention provides a space for excluding the alignment mark 7 from the pressing target at a position facing the alignment mark 7, as illustrated in FIGS. 1 and 2, for example. By using the press body 9 formed with (8), color filter layers 2R, 2G, 2 printed on the glass substrate l as shown in FIG.
The feature is that only the printed surface of B is flattened (smoothed) by press.

That is, as shown in FIG. 2, the color filter layer 2R is formed in stripes.

As shown in the planar configuration of the filter substrate 1 on which the color filters 2G and 2B are printed, the top, bottom, left, and right positions outside the printing area of the color filter corresponding to the display screen are connected to the glass substrate 5 shown in FIG. Alignment mark 7 for positioning
are each printed. Therefore, the press body 9 that presses the printing surfaces of the color filter layers 2R, 2G, and 2B has an alignment mark 7 placed on the part facing the alignment mark 7 from the object to be pressed, as shown by the dotted line in FIG. A groove 8 is provided for exclusion. By using the press body 9 having such grooves 8, the color filter layer 21? , 2G, and 2B are press flattened (smoothed) only on the printed surfaces.

After the printing surfaces of the color filter layers 2R, 2G, and 2B are flattened (smoothed) by the press treatment in the second step as described above, they are dried and solidified in the third step described above. It will be done.

According to this method of manufacturing a color filter, the color filter layer 21?printed on the glass substrate l?
, 2G, and 2B can be press-flattened (smoothed) except for the alignment marks 7, so that the color filter layer 2R can be printed without impairing the alignment accuracy of the alignment marks 7.

The printed surfaces of 2G and 2B can be effectively flattened (smoothed).

Therefore, it is possible to effectively obtain a color filter whose surface is flattened (smoothed), and when assembling a liquid crystal display element using this color filter, it is possible to align it with high precision according to the alignment mark 7. Great practical effects can be achieved, such as making it possible to effectively manufacture a liquid crystal display element without pixel misalignment.

Note that the present invention is not limited to the embodiments described above. Here, the color filter layer 21? , 2
Although an example of press flattening (smoothing) the printed surface of G and 2B has been shown, it can be similarly applied to the case where a roller-shaped press body is used for 2B.

Further, although an example in which the grooves 8 are formed in the press body 9 has been shown here, it goes without saying that holes may also be formed. In addition, the present invention can be implemented with various modifications without departing from the gist thereof.

[Effects of the Invention] As explained above, according to the present invention, a press is used to flatten (smooth) the printed surface of a color filter printed on a predetermined filter substrate in correspondence with the pixels of a display screen. Since a space is formed in the part of the body facing the alignment mark to exclude the alignment mark from being pressed, the entire surface of the color filter layer can be covered without impairing the alignment accuracy of the alignment mark. A color filter that is completely flattened can be easily manufactured.

As a result, it is possible to effectively solve the conventional problem of liquid crystal alignment when incorporated into a liquid crystal display element, and it is also possible to manufacture a liquid crystal display element without causing the problem of pixel misalignment. Great effects can be achieved.

[Brief explanation of the drawing]

FIGS. 1 and 2 are diagrams showing the concept of press processing to explain a method of manufacturing a color filter according to an embodiment of the present invention, and FIG. 3 is a schematic diagram of a liquid crystal display element incorporating a color filter. FIG. 1...Glass substrate (filter substrate), 2R, 2G,
2B... Color filter layer (printed color filter), 3.4... Transparent electrode of liquid crystal display element, 5... Glass substrate, 6... Liquid crystal material, 7... Alignment mark, End: Groove (space that excludes the alignment mark from being pressed), 9: Press body. Figure 1 Figure 2

Claims (1)

[Claims] A color filter corresponding to each pixel of a large screen in which a plurality of pixels are arranged in a matrix is printed and formed on a predetermined filter substrate in a manner corresponding to the size of the pixel; After printing and forming an alignment mark for positioning outside the screen area on the filter substrate, the above-mentioned press body is used, which is provided with a space in a part opposite to the alignment mark to exclude the alignment mark from the press target. A method for manufacturing a color filter, comprising flattening the printed surface of the color filter by pressing the printed surface of the filter substrate.